1. Field of the Invention
The present invention relates to combination fluid valves, and in particular to combination valves permitting bidirectional flow responsive to changes in pressure differential.
2. Description of the Related Art
Current combination fluid valves of the duckbill-umbrella variety having a metal sleeve, which allows the combination valve to be press-fitted into a retainer section of the device in which bidirectional fluid control is required, include a valve body formed of a resilient member. The valve body attaches to the metal sleeve using a retention portion on the valve body and a corresponding lip on the metal sleeve. The valve body is inserted into the metal sleeve with the retention portion pushed past and locking with the corresponding lip. These combination valves are adequate for low pressure applications, such as a water pump for a windshield wiper, for example, but are not acceptable for use at higher pressures, such as in a piston pump for a fuel injection system, for example.
One problem of current combination fluid valves is that at higher pressures the retention portion of the valves are torn away as the pulsing pressure fatigues the resilient material at the retention portion.
Another problem of current combination fluid valves is that the valve body can be damaged when the valve is pressed into position.
It is therefore an object of the present invention to provide a bi-directional umbrella type valve which is suitable for use at higher pressures such as are encountered in fuel injection systems.
The present invention involves a combination valve including a valve body having a duckbill portion and an umbrella portion, and a metal sleeve. The metal sleeve is insert bonded or vulcanized to the umbrella portion and surrounds the duckbill portion to create a very small profile valve with an excellent compression ratio. The metal sleeve has a crenelated end with a plurality of prongs. Gaps located between the prongs of the metal sleeve are used in the process of insert bonding the valve body to the metal sleeve. The prongs on the crenelated end of the metal sleeve allow the combination valve to be pressed into place without damaging the valve body.
The present invention provides a combination valve including a metal sleeve and a resilient valve body. The valve body is integrally bonded to the metal sleeve and includes an elongated member defining a passageway therethrough and an annular portion integral with and extending from the elongated member. The elongated member is disposed within the metal sleeve and defines a plurality of flexible lips.
The present invention also provides a combination valve including a metal sleeve and a resilient valve body. The valve body is integrally bonded to the metal sleeve. The valve body has a first and a second portion. The first portion prevents transfer of fluid in a first direction and is responsive at a first predetermined fluid pressure in a second direction to permit transfer of fluid in the second direction. The second portion prevents transfer of fluid in a second direction and is responsive at a second predetermined fluid pressure in the first direction to permit fluid flow in the first direction.
The present invention further provides a combination valve including a metal sleeve and a resilient valve body. The metal sleeve includes a crenelated end having a plurality of prongs. The valve body is attached to the metal sleeve. The valve body includes a generally planar surface. The prongs of the metal sleeve extend to the planar surface, whereby the valve can be press-fitted into place without damaging the valve body.
The present invention also provides a method of making a combination valve. The steps including providing a mold and a metal sleeve with a crenelated end having a plurality of prongs with gaps therebetween, providing a molding material for forming a resilient valve body, inserting the metal sleeve into a chamber of the mold, forcing the molding material into the mold to form the valve body using the gaps to flow the molding material from the umbrella portion to the elongated member portion of the mold, curing the valve body, and removing the combination valve from the mold.
One advantage of the inventive combination fluid valves is that the valve body is insert bonded to the metal sleeve eliminating the retention portion of prior art valves and allowing the use of the combination valve at higher pressures.
Another advantage of the combination fluid valve is that the combination valve can be pressed into the device in which bidirectional fluid control is required without damaging the valve body due to the prongs of the crenelated end of the metal sleeve extending to the top of the valve body.